MRI appearance of injured ligaments and/or tendons of the ankle in different positions: study protocol for a single-center, diagnostic clinical trial

Abstract

Background: The ankle joint is capable of flexion and extension, including plantar flexion and dorsiflexion, which enables it to act as a lever and a support, and to transmit movement. Ankle joint function is seriously threatened by ankle injury, which is often accompanied by fracture and ligament injury. Previously, diagnosis of ankle injury mainly relied on clinical signs and radiographic examination. However, radiographic examination is insufficient for ankle injury diagnosis, as it cannot clearly diagnose damage to the surrounding ligaments, tendons and other soft tissues. Multisequence and multiplanar MRI is currently the optimal noninvasive method for high-resolution determination of soft tissue deformations, but little has been reported on the diagnostic accuracy of MRI for ankle ligament and tendon injury. Here, we describe our protocol to evaluate the diagnostic value of MRI for ligament and tendon injury of the ankle in its normal position, and during complete plantar flexion and dorsiflexion. Methods/Design: This is a single-center, prospective, diagnostic trial that will be completed at the First Affiliated Hospital of Hebei Medical University, China. Sixty cases have been recruited, including 30 normal ankle joint cases and 30 cases of ankle ligament and tendon injury. All cases underwent MRI with the ankle joint in normal position, complete plantar flexion and complete dorsiflexion, and the multiposition MRI results were compared. The primary outcome measure is the sensitivity of MRI to detect ligament and tendon injury of the ankle during complete plantar flexion. The secondary outcomes include the specificity, positive and negative predictive values, and positive and negative likelihood ratios of MRI for diagnosis of ligament and tendon injury of the ankle in the complete plantar position as well as the rate of correct diagnosis; specificity and sensitivity, positive and negative predictive values, and positive and negative likelihood ratios in normal ankle position or in the complete dorsiflexion position as well as the rate of correct diagnosis; morphology of the ankle on multiposition MRI. Discussion: This study aims to determine the rate of correct diagnosis of ankle ligament and tendon injury using MRI, to clarify the diagnostic value of MRI for ankle ligament and tendon injury, and provide a quantitative MRI diagnostic standard for developing a reasonable surgical strategy. Trial registration: ClinicalTrials.gov identifier: NCT03049423. Ethics: The study protocol was approved by the Ethics Committee of the First Affiliated Hospital of Hebei Medical University in China (approval No. 2015076), and performed in accordance with the guidelines of the Declaration of Helsinki, formulated by the World Medical Association. Informed consent: Written informed consent was obtained from all participants prior to the trial.